Patent GB-460705-A (GB)
Title: Improvements in or relating to arrangements for the reception of electrically transmitted impulses and signals
IPC: H04Q1/45
Filed: 1935-04-29
Abstract: 460,705. Automatic exchange systems. PANSTWOWE ZAKLADY TELE-I-RADJOTECHNICZNE. April 29, 1935, No. 12811. Convention date, Aug. 7, 1934. [Class 40 (iv)] An incoming repeater receives over the junction numerical signals comprising alternate impulses of two different frequencies, the arrangement being such that the correct response is dependent on the duration of the impulses of one of the frequencies. Incoming signals are received through an amplifier KR by relay RA which extends the receiving circuit to a filter adapted to pass 500 cycle current when condensers Cr3, 4 are in parallel and 1000 cycle current when condenser Cr4 is cut out by operation of relay RU. A calling signal comprises successive impulses of 500 and 1000 cycles. Relay RN responds to the first impulse and connects up RQ, whereupon RU, RH respond to the second impulse, holding RQ temporarily and connecting up RK which locks. On the relapse of RH, RQ the outgoing loop is closed to repeat the calling signal, and dialling tone is returned. The numerical signals consist of a succession of impulses of 1000 and 500 cycles alternately. Relays RU, RH respond to the first 1000 cycle impulse and connect up RS which opens one locking circuit of RK. At the end of the impulse, RH falls back, releasing RU by closing a circuit through its opposing lower winding and opening the circuit of RS. Relay RN responds to the 500 cycle impulse and unlocks RK before the relapse of RS which is slow to release, thereby opening the outgoing loop. When RS falls back provided the impulse lasts long enough, RQ energizes and on the subsequent 1000 cycle impulse RH holds RQ so that RS cannot re-operate and RK pulls up again. At the end of the impulse, RH falls back and the loop is reclosed, and after the fourth impulse of 500 cycles, the circuits are in the original condition with RK operated, so that the cycle of operations may be repeated. If, however, any 500 cycle impulse which arrives while RS is up ceases before it falls back, RQ does not energize and the subsequent 1000 cycle impulse holds RS and RK remains back. The repeater is capable of responding also to a succession of impulses starting with a 500 cycleimpulse. In this case the outgoing loop is opened momentarily while RH, RQ are both operated in the manner described above, and RK, RS are unaffected by the signals. The Specification as open to inspection under Sect. 91 describes an outgoing repeater, Fig. 4 (Cancelled), which transmits signals comprising a succession of impulses starting with a 500 cycle impulse. Relay TC which energizes over the test wire connects up TS1, TQ2 and closes the filament circuits of valves KR1, KR2 which generate current of 500 cycles when condensers Crl, 2 are connected in parallel and current of 1000 cycles when condenser Cr2 is cut out. Relay TS connects the output transformer Tr2 to the junction and TS2, TS3 operate slowly in turn to send successive impulses of 500 and 1000 cycles, whereupon TQ2 is disconnected. Line relay TJ1 responds to dialled impulses and TQ1 pulls up at the beginning of each train, so that for each dialled impulse TJ2, TJ3 operate in succession and sent a 500 cycle impulse followed by a 1000 cycle impulse. Upon release by the calling party, TC is held temporarily by sluggish relay TB1 until after release relay TK has fallen back, and on relapsing connects up TQ2 which brings about the successive relapse of TS1, TS2, TS3 to send a clearing signal comprising successive impulses of 1000 and 500 cycles. A modified incoming repeater, Fig. 6 (Cancelled), for three-frequency signalling is also described. The filter therein passes 500 cycle current when condensers Cr3, Cr4, Cr5 are all in parallel, 1000 cycle current when condenser Cr4 is cut out by operation of RU1 and 1500 cycle current when condenser Cr5 also is cut out by operation'of RU2. Relay RN responds to 500 cycle current, relays RU1, RM to 1000 cycle current and relays RU1, RU2, RH to 1500 cycle current. When 1500 cycle current ceases, RU3 pulls up and releases RUl by closing a circuit through its opposing lower winding, thus enabling immediately following 500 cycle current to be received. By the provision of relays RV1, RV2, the releasing circuit of RU1 is completed also when 500 and 1000 cycle current have been received in succession, thus enabling the circuits to respond to signals comprising these two frequencies only. This subject-matter does not appear in the Specification as accepted. 460,740. Diaphragms. EKMAN, O. I. H. Feb. 12, 1936, No. 4233. [Class 40 (iv)] [Also in Group XXXVIII] In a fluid-operated sound-producing device a diaphragm 1 is held between peripheral flanges of members 2, 3 forming a sound-chamber and its periphery is spaced from a concentric washer 5 clamped between the flanges. In a modification, Fig. 2, the diaphragm is of square or rectangular shape and is clamped along one edge. Adjacent the other edge the diaphragm is formed with a series of slots engaged by levers 24 pivoted on knife edge bearings and adjustably secured to the casing 3 by screws 25.